Cks1 is dispensable for survival in Saccharomyces cerevisiae.

Cks1 is a small, evolutionarily conserved protein that was identified due to its genetic interaction with the Cdc28 cyclin-dependent kinase. In S. cerevisieae, Cks1 has long been regarded as a protein essential for cell survival. Here, we describe the derivation of viable cks1 null cells. cks1 null cells are slow growing and exhibit a variety of phenotypes consistent with functions previously described for cks1 temperature-sensitive mutants. In addition, we uncovered additional phenotypes (including a meiotic defect, sensitivity to high salt and inositol auxotrophy), all of which are defects associated with mutations in genes involved in general transcription pathways.